Effect of hormonal contraception on the function of plasmacytoid dendritic cells and distribution of immune cell populations in the female reproductive tract

Abstract

Objective-Epidemiological evidence suggests an association between the use of hormonal contraception and an increased risk of acquiring sexually transmitted diseases including HIV-1. We sought to elucidate the biological mechanisms underlying the effect of hormonal contraception on the immune system.Design-Cross-sectional study.Methods-To delineate the biological mechanisms underlying the effect of hormonal contraceptives on the immune system, we analyzed the functional capacity of circulating plasmacytoid dendritic cells (pDCs), the distribution of vaginal immune cell populations, and the systemic and genital levels of immune mediators in women using depot medroxyprogesterone acetate (DMPA), NuvaRing, or combined oral contraceptives (COC).Results-The use of DMPA or NuvaRing was associated with reduced capacity of circulating pDCs to produce IFNα and TNFα in response to TLR-9 stimulation. Systemic levels of IFNα and cervicovaginal fluid levels of IFNα, CXCL10, MCP-1, and G-CSF were significantly lower in DMPA users compared to control volunteers not using hormonal contraception. The density of CD207 + Langerhans cells in the vaginal epithelium was reduced in NuvaRing and COC users but not in DMPA users.Conclusions-The presented evidence suggests that the use of some types of hormonal contraception is associated with reduced functional capacity of circulating pDCs and altered immune environment in the female reproductive tract.